Headboard unit



FIG. 1 is a right front elevational perspective view of a headboard unit showing my new design;

FIG. 2 is a top view of the headboard unit; and

FIG. 3 is a bottom view of the headboard unit;

FIG. 4 is a front elevational view of the headboard unit; and,

FIG. 5 is a left side view of the headboard unit, the right view being a mirror image in appearance, the rear view having having an outline corresponding to a mirror image of the front view, not having other ornamental design. 

The ornamental design for a headboard unit, as shown and described. 